Subperiosteal hematoma of the iliac bone: imaging features of acute and chronic stages with emphasis on pathophysiology

The goal of this work is to describe the radiological appearance and clinical presentation of subperiosteal iliac hematoma and present a review of the literature. We retrospectively reviewed the radiological and clinical files of 19 patients (age range: 12-75; mean: 47) who presented with acute or chronic subperiosteal iliac hematomas. Imaging findings and relevant clinical information were recorded. A thorough literature search was performed to find additional cases of this rare condition. Three young patients presented with acute subperiosteal iliac hematoma following a fall. Clinical presentation was characterized by pain and gait disturbance presumed to result from crural nerve compression. Unilateral or bilateral lenticular hematomas deep in the iliacus muscle were demonstrated by CT for all patients while MRI was also available for two of them. In 16 asymptomatic patients, chronic ossified subperiosteal iliac hematomas were incidentally detected by CT. Progressive ossification of acute hematoma was demonstrated at follow-up in two patients. Subperiosteal iliac hematoma is rare but has typical imaging findings that may present acutely in adolescents or chronically in asymptomatic adults. (orig.)